This application claims priority of Korea patent Application No. 99-63652, filed on Dec. 28, 1999.
(a) Field of the Invention
The present invention relates to a dual mode shift lever unit for an automatic transmission, and in particular, to a shift switch-actuating mechanism for a dual mode shift lever unit having automatic and manual modes, which is capable of providing reliable shifts in manual mode and is simplified by having a reduced number of parts.
(b) Description of the Related Art
Recently, high-class automobiles have tended to be equipped with a dual mode transmission mechanism for satisfying driver whimsical tastes to sometimes manually shift the transmission like a sports car, and sometimes to enjoy ride quality of an automatic operation of a high-class sedan.
This kind of dual mode shift lever unit provides two shift modes, i.e., an automatic mode and a manual mode, such that an indicator panel is formed having a guide groove separating respective mode portions, as shown in FIG. 1.
The dual mode shift lever unit comprises a shift lever slidably inserted into the guide groove formed on the indicator panel and a cable block connected to a transmission manual valve by a cable.
Normally, when the shift lever unit is in the automatic mode, the shift lever is fixedly connected to the cable block such that the transmission manual valve is responsively operated by shift lever manipulation.
On the other hand, when the shift lever unit is in the manual mode, the shift lever is separated from the cable block such that the shift lever freely moves.
Also, the dual mode shift lever unit has a shift switch-actuating mechanism mounted on the upper wall of a lever housing below the indicator panel so as to be operated in the manual mode. FIG. 5 is a conventional shift switch-actuating mechanism of the dual mode shift lever unit.
In the manual mode, the shift lever is located between reaction means 104 and 105 which respectively include a cylinder 106, a piston rod 108, and a coil spring 107 biasing the piston rod in the cylinder 106 such that the shift lever is returned to the neutral position after up or down shift manipulation. The piston rod 108 is provided with a switch depressor formed at a distal end of the piston rod 108 for actuating a corresponding switch.
Along the lever""s movement line, up and down shift switches 101 and 102 are mounted and a manual mode switch 103 is arranged therebetween such that whenever the shift lever 2 is manipulated for an up or down shift, the shift lever 2 causes a corresponding switch to be on. Accordingly, a TCU (transmission control unit), now shown, responsively controls the transmission on the basis of electrical signals from the switches 101, 102, and 103.
In this shift switch-actuating mechanism, however, it is difficult to maintain a distance between the switches and the switch depressors, and since the switch depressors move in vertical directions relative to the switches"" working directions, the switching operation is unreliable.
Furthermore, it is difficult to manufacture the small reaction means, and the manufacturing is expensive.
The present invention has been made in an effort to solve the above problems of the prior art.
It is an object of the present invention to provide a shift switch-actuating mechanism for a dual mode shift lever unit which is capable of providing reliable shifts in manual mode and being simplified by reducing the number of parts, resulting in low manufacturing costs.
To achieve the above object, a shift switch-actuating mechanism for a dual mode shift lever unit is provided, including a shift lever pivotally connected to a pivot shaft supported by a lever housing and a cable block pivotally mounted on the pivot shaft outside the lever housing, the lever housing having an opening on its wall facing the cable block such that the shift lever and the cable block interact with each other. The the shift switch-actuating mechanism is mounted on an upper wall of the shift lever housing below an indicator panel so as to be operated in a manual mode, and it comprises a base plate having an indented portion for receiving the shift lever, an up shift switch mounted on the base plate for detecting up shift manipulations of the shift lever, a down shift switch oppositely mounted on the base plate for detecting down shift manipulations of the shift lever, a manual mode switch mounted inside the indented portion of the base plate for detecting manual mode conversion of the shift lever, and a switch actuator mounted on the base plate between the up and down shift switches for selectively operating the up and down shift switches, the up and down shift switches being oppositely arranged so as to cross over the indented portion of the base plate, and one end of the switch actuator is projected into the indented portion.